I have read a lot of the posts on r&r of the water pump for the 4.6L Northstar. I have the tool, loaner from Autozone, and am having great difficulty with it not slipping off under the pressure it takes to try and remove the impellar. I am using a 30 inch cheater bar on a 1/2 inch breaker bar attached to the tool. I even had Autozone give me a second tool since the first loaner was a bit beat up and some of the corners rounded off. The current tool is like new with sharp edges.

The question is this, I have seen at least one person say that they needed to use an impact wrench to break the impellar loose. I have seen others say that this is not needed. How do you keep enough pressure on the tool so that you can turn it or should I borrow an impact wrench and try that, and hopefully not damage the housing? I have had a buddy try and put pressure against the tool while I am on the cheater bar and even that did not break it loose. How do they do this in professional service bays?

Submariner409

08-14-08, 03:45 PM

Some do, in fact, use an impact wrench set on low hammer. Remember that the pump turns clockwise to come out.

jakes95sls

08-14-08, 03:51 PM

Thanks, yes, all the turning effort has been clockwise. It just isn't breaking loose and I can't see how someone can do this as a one person job without using an impact. I have just seen some say that that may not be safe to the housing, but don't see how I can get this stubborn thing out without one.

Submariner409

08-14-08, 04:01 PM

Hmmmm......If you still haven't had any luck, stuff rags under the housing/crossover and wet down the pump O-ring flange area with PB Blaster and let it sit overnight. Some have posted corrosion found in there......

jakes95sls

08-14-08, 04:14 PM

Submariner: if I understand you correctly, I have already used PB Blaster and let it set overnight. I sprayed the pump area around all of the tabs where they are turned under the housing flange tabs. Maybe another soaking will do before I resort to the impact wrench. Thanks

I think you could fashion something similar yourself, but maybe you just need a buddy to hold the tool you already have in place while you try to turn it clockwise. Make sure you have the tool engage in the correct place before turning.

Be careful with that water pump housing - it is part of the coolant crossover, which is a royal PITA to change if you screw it up. The crossover gaskets do leak sometimes, so it is not unheard of to have to R & R the coolant crossover, but you don't want to do it if you don't have to!

Tateos,thanks for the reply. All the water pump sockets should come with this based on my experience! This looks like something easy enough to build and something everyone should have before starting this task.

I can't tell exactly where the leak is, and based on the forum, am hoping it is just the water pump and not the crossover, 'cause I really don't want to be doing that job. This one was so simple until I get the stuck impellar.

tateos

08-14-08, 06:36 PM

Actually, I have removed a NS water pump a few times without a problem. The first time was a little scary because of how hard you have to turn the breaker bar to get the water pump to snap loose. You will be amazed at how easy it is to re-install.

Oh - BTW, I don't think you can damage the housing with the impact wrench - not sure about that, but remember, you are prying on the steel water pump tabs - not the aluminum housing, so as long as you stop once it is loosened, I think you should be all set, no matter how you do it

Ranger

08-14-08, 07:02 PM

Try a few short burst from an impact. If that does not work, them make the strap. I made the socket in case I'd ever need it. Haven't yet so it was good insurance, but I didn't make the strap. Guess I'll make that when and if I need it.

CadillacSTS42005

08-14-08, 11:32 PM

id use a nice breaker bar
i wouldnt use an impact for fear of hitting it too hard and jamming it in

Edahall

08-15-08, 11:32 AM

I'm one who ended up having to use a rather large impact wrench to remove my waterpump. I didn't have an impact wrench so started off with a impact wrench (with 5 ft cheater bar) but ended up breaking it as well as my Kent Moore waterpump tool. I ended up having to buy another tool and borrowing a large impact wrench.

jakes95sls

08-15-08, 10:29 PM

So, the Cadi gods must be with me today, or I hope. After another soaking of PB Blaster left overnight, today I saw that the tabs had actually moved some in my last attempt with my buddy and then with one more small push with the breaker bar the impellar broke loose. So, no impact was needed.

Some lessons learned though for those who may attempt to remove the water pump on the Northstar in the future. I would either not attempt this alone or if you do, buy or make the strap that tateos mentioned above. Also, with the several attempts that I had made and with the socket slipping off the impellar I found some metal filings in the housing, so I removed these with a magnet. I don't think you want this in your cooling system and if you are like me and strip some of the metal off with the socket slipping, look for this. To keep the O ring in place I bought some Permatex Ultra Rubber Gasket Sealant, but this stuff is so sticky and I had trouble seating the O ring in the groove, so I cleaned it off and used Permatex Blue RTX Silicone instead, which worked much better at seating the ring. Now after 24 hours to cure the Blue I will finish, test and hope I don't have further leaks with the crossover.

rollman

08-25-08, 05:59 PM

So, the Cadi gods must be with me today, or I hope. After another soaking of PB Blaster left overnight, today I saw that the tabs had actually moved some in my last attempt with my buddy and then with one more small push with the breaker bar the impellar broke loose. So, no impact was needed.

Some lessons learned though for those who may attempt to remove the water pump on the Northstar in the future. I would either not attempt this alone or if you do, buy or make the strap that tateos mentioned above. Also, with the several attempts that I had made and with the socket slipping off the impellar I found some metal filings in the housing, so I removed these with a magnet. I don't think you want this in your cooling system and if you are like me and strip some of the metal off with the socket slipping, look for this. To keep the O ring in place I bought some Permatex Ultra Rubber Gasket Sealant, but this stuff is so sticky and I had trouble seating the O ring in the groove, so I cleaned it off and used Permatex Blue RTX Silicone instead, which worked much better at seating the ring. Now after 24 hours to cure the Blue I will finish, test and hope I don't have further leaks with the crossover.

Did this fix cure your leak problem . I think the pump on my STS is leaking so I'm searching to see how hard this replacement job is . I hate to even think how much the dealer wants .

tateos

08-25-08, 06:59 PM

So, the Cadi gods must be with me today, or I hope. After another soaking of PB Blaster left overnight, today I saw that the tabs had actually moved some in my last attempt with my buddy and then with one more small push with the breaker bar the impellar broke loose. So, no impact was needed.

Some lessons learned though for those who may attempt to remove the water pump on the Northstar in the future. I would either not attempt this alone or if you do, buy or make the strap that tateos mentioned above. Also, with the several attempts that I had made and with the socket slipping off the impellar I found some metal filings in the housing, so I removed these with a magnet. I don't think you want this in your cooling system and if you are like me and strip some of the metal off with the socket slipping, look for this. To keep the O ring in place I bought some Permatex Ultra Rubber Gasket Sealant, but this stuff is so sticky and I had trouble seating the O ring in the groove, so I cleaned it off and used Permatex Blue RTX Silicone instead, which worked much better at seating the ring. Now after 24 hours to cure the Blue I will finish, test and hope I don't have further leaks with the crossover.

Thanks for the upate

deantreat

08-16-11, 03:17 PM

My pump removal with new removal socket from auto zone has gone like this: the socket feels as though it is seated, and I can get appx 20some degrees
rotation clockwise, using long handle ratchet, but the pump does not come out. I can turn it counter clockwise about the same amount. Is there something I can do once I've reached its limit of clockwise travel, to unseat the damn pump? I need to get past this step because the drive pulley removal and install is waiting (not sure how that is gonna go).

Submariner409

08-16-11, 03:33 PM

That pulley/shaft/impeller capsule should come out at 30 - 35 degrees CW rotation. Hopefully one or more lock tangs aren't bent. The GM pump socket has a strap with a hole in it which bolts over the socket in order to keep the socket firmly in place - your helper technique is the way to go.

Remember to correctly orient the new capsule. One tang is different.

A good Northstar water pump capsule socket costs about $100...............